heyy r u the guy that made the wolfram website? with physics and astronomy and chem and biology stuff? scienceworld.wolfram.com? i like that website but its a bit too much like a dictionary, u should include more pictures and maybe examples.

Is there any cosmological observation that would suggest that once a star
goes nova that its elements will not be recycled into another star, planet
what ever ?

I presume that you mean supernova. If so, then yes, there have been observations of huge ISM clouds containing "heavy" elements but which are not star forming regions. Some of these are galactic but many are intergalactic. That doesn't mean that some of the material can't or won't end up in an object like a star or planet, etc., but with the expulsion rate and direction of this matter it is highly unlikely that all of it could ever end up re-condensing into stellar or planetary material.

I presume that you mean supernova. If so, then yes, there have been observations of huge ISM clouds containing "heavy" elements but which are not star forming regions. Some of these are galactic but many are intergalactic. That doesn't mean that some of the material can't or won't end up in an object like a star or planet, etc., but with the expulsion rate and direction of this matter it is highly unlikely that all of it could ever end up re-condensing into stellar or planetary material.

I will not question your knowledge, but were is, "out of bounds", for star
formation? and why ?

I will not question your knowledge, but were is, "out of bounds", for star
formation? and why ?

I suppose that could be just about anywhere that the ISM is too tenuous and / or has too much dispersing velocity for gravitational attraction to be strong enough to cause any collapse toward the formation(s) of protostar or protoplanetary condensations. Also, such a protostar collapse could be of such a small amount of matter that nothing is formed other than an concentration of ISM material of higher density, but still quite tenuous.

I will not question your knowledge, but were is, "out of bounds", for star
formation? and why ?

If it remained bound to the galaxy, then given enough time, I would expect the vast majority of gas to end up in either stars, black holes, or some other compact object. It's certainly true that a hot gas will not be able to immediately collapse to form stars, but gas cools and the galaxy is not a closed system, so it would not remain hot forever.

However, note that I specified that the gas remain bound. Energy input from supernovae can sometimes provide enough of a "kick" to allow the gas to escape the galaxy and, perhaps, the local group or cluster. It then becomes dispersed in the surrounding medium. Now one might suspect that the same arguments apply there as to inside the galaxy; that is, the gas will eventually cool and collapse. However, there is another factor to consider -- the expansion of the universe. In a traditional cold dark matter universe (minus dark energy), structure formation continues as long as the expansion does and everything will eventually become incorporated into a gravitationally bound entity. However, a universe with, say, a cosmological constant, will cease forming structures on some specific physical scale. If the "dark energy" in our universe really is a cosmological constant, then this scale will be about that of galaxy clusters (~100 Mpc).

What does this mean? Well, basically, if you can succeed in dispersing the gas over scales greater than that which can gravitationally collapse, presumably you can prevent that gas from ever forming stars. We certainly do observe gas dispersed over those scales, but we are still unsure about how much of it is primordial and how much was ejected from galaxies.

Thanks, Lab guy, Space Tiger, your answers are informative, but if i may, i will
say the question is still open.

This question:

"Is there any cosmological observation that would suggest that once a star
goes nova that its elements will not be recycled into another star, planet
what ever ?"

is not 100% clear to me. If you're asking whether some supernova ejecta gets recycled in later generations of stars, then the answer is a definite yes. If the question is whether or not all such debris will eventually be in stars, planets, or whatever, then it depends on what you're including in the "whatever".

"Is there any cosmological observation that would suggest that once a star
goes nova that its elements will not be recycled into another star, planet
what ever ?"

is not 100% clear to me. If you're asking whether some supernova ejecta gets recycled in later generations of stars, then the answer is a definite yes. If the question is whether or not all such debris will eventually be in stars, planets, or whatever, then it depends on what you're including in the "whatever".